With finales and penultimate episodes aplenty, Monday was a good night for the five networks, which all posted gains over last Monday’s numbers. There was good news for “How I Met Your Mother” and “Chuck,” which both got boosts for their finales and also for “House,” which took a big jump from last week heading into next Monday’s finale.

Mostly, though, the news was good for ABC, as “Dancing with the Stars” and “Castle” both delivered strong performances and carried the network to an easy Monday ratings sweep.

Among adults 18-49, ABC averaged a 4.1 rating for the night, tops in the key demographic. FOX was well back in second with a 2.7 rating, just ahead of the 2.5 rating for CBS. NBC’s 1.3 rating and the 0.8 rating for The CW trailed.

Overall, ABC averaged an estimated 18.68 million viewers to go with an 11.6 rating/18 share. CBS was a distant second with a 5.1/8 and 8.01 million viewers, topping FOX’s 4.5/7 and 7.39 million viewers. NBC was fourth with a 2.7/4 and 4.265 million viewers, leaving The CW in fifth with a 1.0/2 and 1.49 million viewers.

8 p.m. – “Dancing with the Stars” began primetime in first with 19.84 million viewers and a 3.9 rating among adults 18-49. FOX’s “House” improved by more than half-a-demo-rating with a 3.5 rating and averaged 8.85 million viewers, up by over a million. CBS was third with “How I Met Your Mother” (7.11 million and a 3.0 demo rating) and the series finale for “Mad Love” (5.81 million and a 2.1 rating). On NBC, perennial bubble-beater “Chuck” was up a bit to 4.67 million viewers and a 1.5 demo rating. The CW’s “90210” averaged 1.65 million viewers and a 0.8 demo rating in fifth.

9 p.m. – The second hour of “Dancing with the Stars” rose to 22.985 million viewers and a 5.0 demo rating. CBS was a distant second with a repeat of “Two and a Half Men” (6.92 million and a 2.0 demo) and a new “Mike & Molly” (8.57 million and a 2.5 demo). Even after being canceled, “The Chicago Code” got a tiny bump to 5.92 million viewers and a 1.9 demo rating in third, beating the 4.01 million viewers and 1.3 demo rating for NBC. The CW’s “Gossip Girl” was fifth with 1.335 million viewers.

10 p.m. – The shocking “Castle” finale gave ABC 13.21 million viewers and a 3.3 demo rating to rule the 10 p.m. hour. CBS was second with the 9.83 million viewers and a 2.5 demo rating for “Hawaii Five-0.” NBC’s canceled “Law & Order: Los Angeles” was third with 4.32 million viewers and a 1.1 demo rating.

All ratings information comes from preliminary Fast National Nielsen data, which includes live and same-day DVR viewing. All numbers are subject to change.